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2016FallShotcreteEMag

Pool & Recreational Shotcrete Corner it takes to change mindsets and introduce more professionals to the need for excellence in shotcrete application. Fortunately, the industry has significantly increased the strength and credibility of educational programs related to shotcrete in recent years—indeed, there’s now a wealth of resources dedicated to bringing watershapers up to speed with good and accurate information and the best of the available courses and collateral materials for both wet and dry shotcrete are based on guidelines established by the American Concrete Institute (ACI) and the American Shotcrete Association (ASA). What this means is that, with fair consistency, programs now offered by groups as diverse as the National Swimming Pool Foundation (NSPF), the Genesis Group, the Northeast Spa & Pool Association (NESPA) and the National Plasterers Council (NPC) are in large part aligned with the principles governing ACI’s Nozzleman Certification program and ASA’s technical review courses. This is a good situation that will only get better with time. In fact, these programs are already starting to pay noticeable dividends. Many specifiers and engineers are already looking to ACI and ASA as standard-setters for key performance indicators including compressive strength and water-cement ratios. More important, these watershapers are incorporating the ACI/ASA indicators into their bid specifications, effectively binding contractors to follow protocols per contract terms. Have all aquatic designers rejected the notion that concrete watershapes require waterproofing? Not universally by any means, but more and more of these professionals are calling these days for watertight shotcrete installation before any surface finish may be applied. At the Nozzle The importance of expanding participation in ACI Nozzleman Certification within the contractor community cannot be overstressed. In fact, its value is so widely appreciated already that more and more large shotcrete subcontractors are seeking ACI certification for their workforces. It’s even reaching a point where such credentials are a basic indicator of proficiency recognized by design professionals, general and specialty contractors, and clients. This certification isn’t a guarantee of quality, but those with the certification are expected to understand the process, know what to expect as application moves forward, and are on a determined path to greater proficiency. Of course, it also takes extensive experience on top of basic certification to achieve excellence with complex, high-end watershapes—yet, even basic certification is helpful when watershapers compare the credentials of different shotcrete companies. Another indicator of this new, more rigorous attitude in evaluating shotcrete companies is the fact that more and more plastering companies are taking a harder look at shotcrete and the effects it can have on their finishes. The NPC, for instance, has incorporated relevant information in its educational courses, helping its membership know how to size up a shotcrete job and make smart decisions in the field about whether to move forward with their own work. Finally, shotcrete contractors themselves are taking ownership of their mixture designs and their expectations about the material being supplied to them by ready-mix suppliers. There is, for instance, a growing awareness of the detrimental effects that low quantities of cement binder material in the mixture has on the final product. So considerable progress has been and is being made, which is the good news. The bad news is that there are still persistent pockets of old-school thinking—even in the education scene—that threaten to undermine the gains we’ve all made. The Association of Pool & Spa Professionals’ Builders Manual is a case in point: it includes a variety of quality information on overall pool requirements which we at Drakeley Pool Co. use regularly. But it also offers blatantly incorrect and/ or outdated information on some of the structural aspects of shotcrete construction. It’s time to break away from the old-school suppositions and from instruction based on anecdotes and personal preference that is too often given equal time alongside scientific, fact-based criteria established by ASA and ACI. It’s also time for professionals on the periphery of watershaping to shrug off their reliance on dubious opinions and old-school approaches. Many engineers, for instance, do not encounter robust education on shotcrete, which is why so many of them are, to this day, wedded to a belief that casting in place is superior to pneumatic application—and have difficulty focusing on alternatives as a result. Making things even more difficult is the fact that many of these traditionalist engineers had negative experiences with shotcrete that occurred years ago—long before attitudes and approaches to the shotcrete process began to recover and improve. 38 Shotcrete • Fall 2016


2016FallShotcreteEMag
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